Question 222842
If the question had been 12-6=n, then the answer would have been n=6.


However the question was 
12-6=-n
6=-n


Divide both sides by -1:
{{{6/-1=(-n)/-1}}}
{{{-6=n}}}

{{{n=-6}}}


Check:  

12-6=-n
6=-(-6)
6=6  It checks!!


R^2


Dr. Robert J. Rapalje
Seminole State College of Florida
Altamonte Springs Campus